I have a (new) PMO issuing a Good Scheduler Practices instruction prohibiting the use of any form of explicit delay allowance or time buffer in our project schedules on the basis that it only extends the project duration and / or confuseres the crical path.
Also, no use of any Start as Late as Possible activity logic.
Am in the electricity distribution industry and projects usually take 4 - 5 years with critical path running through network planning, site aquisition, building design, construction, electrical (power distribution) fitout, and commissioning.